I have one of these cheap multimeters, and when set to continuity/diode setting, and the probes touched together, the 20mm piezo makes a scratchy, muffled, weak noise, barely noticeable. The display does show the response, going from "1" to "0.00".
The piezo is ok, I transplanted it to a similar multimeter, and it makes a nice loud tone. I tried a couple of smaller piezos, the type pulled off old motherboards (12mm type), and it makes the same scratchy, muffled noise.
However, I did find a bigger piezo (about 22mm diamter), that I think was pulled off a UPS board, and when I try with this in place of the original piezo, it makes a nice loud noise. But whereas the other piezos are just a piezo, this one that works has some extra circuitry built in (picture 3).
So it looks like there is something wrong with the electronics going to the original piezo on the DMM board. Will the multimeter have a similar circuit to the 22mm piezo somewhere?
Is it possible to get a smaller piezo with a circuit inside it like the bigger 22mm piezo? I couldn't get the bigger piezo to fit the case, but a smaller 12mm piezo with a circuit built in could fit in one of the corners of the multimeter case, if there is such a thing.
Are there any other viable options?
The piezo is ok, I transplanted it to a similar multimeter, and it makes a nice loud tone. I tried a couple of smaller piezos, the type pulled off old motherboards (12mm type), and it makes the same scratchy, muffled noise.
However, I did find a bigger piezo (about 22mm diamter), that I think was pulled off a UPS board, and when I try with this in place of the original piezo, it makes a nice loud noise. But whereas the other piezos are just a piezo, this one that works has some extra circuitry built in (picture 3).
So it looks like there is something wrong with the electronics going to the original piezo on the DMM board. Will the multimeter have a similar circuit to the 22mm piezo somewhere?
Is it possible to get a smaller piezo with a circuit inside it like the bigger 22mm piezo? I couldn't get the bigger piezo to fit the case, but a smaller 12mm piezo with a circuit built in could fit in one of the corners of the multimeter case, if there is such a thing.
Are there any other viable options?
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